a. Field of the Invention
The present invention relates to the field of electrical power connectors, and in particular power connectors that are used to connect a source of mains power to an item of electrical equipment.
b. Related Art
Items of electrical equipment used in the home or office environments may be connected to the mains supply by means of a power cable that has one end plugged into a mains wall socket. Instead of being permanently wired, the other end of the cable may terminate with a line socket that can be plugged into a matching plug. When the plug is provided on the chassis of the equipment, this is called a chassis plug or a panel plug.
The most common examples of such power connectors are those that adhere to the standards defined by the International Electrotechnical Commission (IEC) specification IEC 60320, particularly the C13 ad C14 connectors used with personal computer equipment and peripherals.
Some types of power connector are also available as line plug and panel socket versions, but these are less common. In the IEC specification, the term “connector” refers to line sockets (or panel sockets) and the term “inlet” refers to panel plugs (or line plugs).
The IEC standard includes two and three-conductor plugs of various current capacities and temperature ratings, all designed specifically for the purpose of attaching a mains power cord to a piece of electrical equipment. One of the main advantages of the IEC connector standard is that this allows for an interchangeable mains power cord, making it very easy for equipment manufacturers to sell their equipment anywhere in the world as long as their equipment can operate on both 120/240 volt, 50/60 Hz mains power.
One disadvantage of such connectors and inlets is that the joined connector and inlet can readily be pulled apart, which can happen when equipment is moved about or when a force is applied to the connecting cable resulting in an unexpected loss of power to equipment that is in use.
Patent document GB 2383202 A therefore proposes that a line socket has a power pin receptacle inside of which is a pivoting latch plate that has edges that allow a power pin to enter the receptacle but which dig in to the power pin when this is pulled in the opposite direction. The power pin, and hence the rest of the panel plug, are therefore locked to the line socket.
The pivoting latch plate is biased by means of a coil spring towards the orientation in which the edges dig into the engaged power pin. The spring acts on an elongate slide piece which when moved against the biasing force of the spring along an axis parallel with the power pin insertion direction causes the latch plate to pivot towards an orientation which the latch plate edges no longer dig in to the engaged power pin. The slide piece has a catch that extends transversely from an end of the slide piece out of a slot in the main body of the line socket so that the slide piece can be manually moved to release the line socket from the panel plug when this is desired.
This arrangement works well but is only suitable for use with a line socket and a panel plug, not a panel socket and a line plug. This is because the elongate slide pin extends away from the front face of the socket into the body of the socket. It is only because the line socket has an accessible main body portion that the transverse latch on the slide portion can be manually accessed to manually move the elongate slide pin to release the locking mechanism. Such an arrangement is not possible with a panel socket where the main body of the panel socket will normally be concealed behind a surrounding panel or face plate.
It is an object of the present invention to provide a locking power connector apparatus having a panel socket.